26. Write Blockers

• Two types of the write blockers exist:

  • Hardware

  • Software

• A hardware write protector is a device that sits in the connection between a computer and a storage device.

• A software write blocker modifies the interrupt table so that the table entry for BIOS interrupt 13h re-points the OS address to the write blocker in memory.

• When any software requests to Write Sectors To Drive, the write blocker prevents that from happening.

• See also cftt.nist.gov/software_write_block.htm